1. Field of the Invention
This invention relates to an interlocking device for a small size push button switch which has a simple mechanical construction and effects accurate interlocking.
2. Description of the Prior Art
In a push button switch, an interlocking device which prevents two push buttons from being pushed down simultaneously is required in order to avoid breaking of the switch caused by simultaneous operation of two push buttons.
Commonly used interlocking devices for push button switches are disclosed, for example, in Japanese Utility Model Registration Application Publications No. 32-551 and No. 39-28139. These devices have a construction in which an interlocking rod is disposed between two adjacent push buttons for movement in a lateral direction in a switch so that when either one of the two push buttons is pushed down, the interlocking rod is moved toward the other push button for locking it against movement.
The above conventional interlocking system has a complicated construction, requires many parts and is difficult to assemble, especially in the case where spring and balls are used.
The present invention has been made in view of the drawbacks of the conventional devices.